Gas turbines generally operate by combusting a fuel and air mixture in one or more combustors to create a high-energy combustion gas that passes through a turbine, thereby causing a turbine rotor shaft to rotate. The rotational energy of the rotor shaft may be converted to electrical energy via a generator coupled to the rotor shaft. Each combustor generally includes fuel nozzles that provide for premixing of the fuel and air upstream of a combustion zone, as a means to keep nitrogen oxide (NOx) emissions low.
Gaseous fuels, such as natural gas, often are employed as a combustible fluid in gas turbine engines used to generate electricity. In some instances, it may be desirable for the combustion system to be able to combust liquid fuels, such as distillate oil, with no changes to the combustion hardware. A configuration with both gas and liquid fuel capability is called a “dual-fuel” combustion system. In a typical configuration, liquid fuel injection may be provided via a cartridge that extends within a centerbody of the fuel nozzle. While serving as an effective means for delivering the liquid fuel to the combustion zone of the combustor, the cartridge increases overall component count and cost of assembly.